Full Resolution: Mankind is probably the main cause of global warming in current times.

== Rules ==

1. No forfeits
2. All arguments must be within the debate, while citations or end/footnotes can only be within the debate, in the comments section, or as a cancelled debate on DDO linked if the location is specified
3. No new arguments in the final round (except for defense of constructive cases)
4. Maintain a civil and decorous atmosphere
5. No trolling
6. No "kritiks" of the topic
7. My opponent accepts all definitions and waives his/her right to add resolutional definitions
8. For all undefined terms, individuals should use commonplace understandings that fit within the logical context of the resolution and this debate
9. The BOP is shared

== Debate Structure ==

First round acceptance only. The second round is for constructive cases only (no rebuttals). The third round is for rebutting constructive cases, without defending one's own arguments. The fourth round is for defending one's own arguments and a summary, without rebuttals. No new arguments in the final round except for the defense of one's own arguments.

== Definitions ==

Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century, and its projected continuation. [1] Mankind is "the human race; human beings collectively without reference to sex; humankind." [2] "Probably" is defined as "very likely." [3] To clarify this, I will argue that there is a probability of more than 50% that mankind is the main cause of global warming. "Main" is "chief in size or importance." [4] "Cause" is defined as "a person or thing that gives rise to an action, phenomenon, or condition." [5]

I accept and to clarify as my opponent is stating there's a larger than 50% chance, I am saying that there is a smaller than 50% chance mankind is the main cause of global warming in current times. I look forward to my opponents opening argument

The scientific opinion on climate change is clear that mankind is probably the main cause of global warming. In fact, a survey has concluded that there are no scientifically relevant studies that provide a direct rebuttal to the idea that mankind is the main cause of global warming. [1] The IPCC, the American Meteorological Society, American Geophysical Union, and the American Association for the Advancement of Science all agree that the evidence for human-caused global warming dominating climate change is overwhelming and clear. [1] "That humans are causing global warming is the position of the Academies of Science from 80 countries plus many scientific organizations that study climate science. More specifically, around 95% of active climate researchers actively publishing climate papers endorse the consensus position." [2] A study by Doran (2009) found that 82% of climate scientists with a master degree or Ph.D agreed that mankind is the main cause of global warming. [3] NASA agrees, and notes that "most of the leading scientific organizations worldwide have issued public statements endorsing this position . . . Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities." [4] A report written by 28 scientists representing 13 governmental agencies has stated, "The global warming of the past 50 years is primarily due to human-induced increases in heat-trapping gases." [5]

C2) Human-induced increases in carbon dioxide

All scientists agree that carbon dioxide traps heat. That carbon dioxide traps heat is basic physics. Excess carbon dioxide traps heat. Harries, et al. (2001) finds "direct experimental evidence for a significant increase in the Earth's greenhouse effect" at the wavelength bands where carbon dioxide and methane trap heat. [6] The debate on carbon dioxide comes down to "climate sensitivity," defined as the increase in global land-sea mean temperature per doubling of carbon dioxide concentration in the Earth's atmosphere. All serious skeptical scientists and supporters of global warming agree that -- in a default state -- the climate sensitivity is likely 1.1 degrees Celsius. [7] The argument is about feedbacks.

What are feedbacks? Feedbacks are mechanisms -- such as clouds and volcanic activity -- that amplify or dampen the effect that carbon dioxide has on temperature. The mechanisms that amplify the effect are called positive feedbacks, while those that dampen it are called negative feedbacks. [8] I argue that positive feedbacks dominate climate. Many studies agree. "Since the radiative effects associated with the buildup of water vapor to near-saturation levels and the subsequent condensation into clouds are far stronger than the equilibrium level of radiative forcing by the non-condensing GHGs, this results in large local fluctuations in temperature about the global equilibrium value." [9] This is demonstrated in the below graph:

In simpler explanation, a feedback amplifies the effect of a forcing -- in this case, carbon dioxide. Using a Bayesian statistical approach, which is the "dominant" method in the literature, one can conclude that the average climate sensitivity is four degrees Celsius. [9] It is empirically demonstrable that climate sensitivity is at least three degrees Celsius. CO2 concentrations have increased from around 275 ppm to 400 ppm -- a 40% increase. This should manifest itself with a temperature increase of a little less than 1.5 degrees C. And temperature levels have increased precisely to this amount. [10] Below is a graph that showcases how much sensitivity different studies have found. [13]

The following picture demonstrates the evidence that shows a climate sensitivity of around 3 degrees Celsius.

It is well-known that CO2 levels are increasing. The below graph shows a direct rise in CO2 levels. [11]

Much of CO2 increase is human-induced. "In pre-industrial times over the last 10,000 years, CO2 was relatively stable at around 275 to 285 parts per million. Over the last 250 years, atmospheric CO2 levels have increased by about 100 parts per million." [12]

C3) Paleoclimatology suggests that mankind causes global warming

Multiple paleoclimate records suggest that CO2 has a direct effect on climate change. According to many studies, after the beginning of the Cenozoic Era 65.5 million years ago, carbon dioxide has been the dominant climate forcing. [14] The sun increased slightly over that time period, whereas temperatures cooled. CO2, however, fell steadily through that time period. An ideal example of this is the Vostok ice cores. "There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2 (Barnola et al. 1987). The extension of the Vostok CO2 record shows that the main trends of CO2 are similar for each glacial cycle. Major transitions from the lowest to the highest values are associated with glacial-interglacial transitions. During these transitions, the atmospheric concentrations of CO2 rises from 180 to 280-300 ppmv (Petit et al. 1999). The extension of the Vostok CO2 record shows the present-day levels of CO2 are unprecedented during the past 420 kyr." [15] The below graph documents the correlation between increase in CO2 concentration and rise in temperature over 700,000 years.

In fact, 2014 was the warmest year since 1400, suggesting that increased human activity drives climate change. Therefore, I conclude that human emissions increase temperatures, and, thus, mankind is the main cause of global warming.

(1) Con presented an argument as a Google Doc in the comments. That Google Doc is *inaccessible,* since Con didn't make it a shareable link. Only Con can see that Google Doc, and I'm unable to see it. Therefore, it is equal to a forfeit.

(2) Con ran out of time and forfeited, so it's only fair that it be considered a forfeit.

Regardless, my opponent was *out of time* on the R2 argument. Extend Point 2 - it's only fair that it be considered a forfeit, since they took more time for their arguments. The time was reset, so my opponent did forfeit due to time. As such, one cannot circumvent the time limit by such means.

Therefore, vote Pro. This is -- by default -- a forfeit, since my opponent ran out of time. Rule 1 says that forfeits will not and cannot be permitted.

The next round must be passed, as there cannot be any new arguments in the final round.